Pay no attention to that band behind the curtain. (Or in the orchestra pit.) Not that you’ll necessarily need to. In the touring version of “The Wizard of Oz” that wraps on Sunday at the Civic Theatre, there almost isn’t one.

Patrons scanning their programs at the show, presented by Broadway/San Diego, may be startled to see it lists just three musicians — a keyboardist, a trumpet player and a drummer-percussionist — plus a musical director/conductor.

Even by the standards of a non-union tour such as this one, that’s tiny. By comparison, Broadway/San Diego’s recent Equity (union) presentation of “West Side Story” employed 18 musicians, 15 of them locally based. On Broadway itself, orchestras tend to be even larger: There are 23 musicians in the still-running “Oz” spinoff “Wicked” (although that show’s touring versions typically have smaller orchestras).

It’s a different story for rock musicals: The touring version of “Next to Normal” that Broadway/San Diego brought to the Balboa Theatre in January had a seven-member band, two of them local.

But “The Wizard of Oz” is no rock musical; it features essentially the same score as the iconic 1939 movie. So where do all those strings and other orchestra-like sounds in the show come from? The answer lies in a separate credit given to keyboardist Jonathan Loving: “Notion operator.”

Notion is a software program that musicians can use, in the words of the manufacturer’s Web site, “to bring the magic of a full orchestra” to a production. The site boasts that Notion also has been used in touring shows from “The Producers” to “Dirty Rotten Scoundrels.”

But is simulating “the magic of a full orchestra” the same as having a live orchestra playing in the pit? (Never mind that the “Wizard” program does indeed describe the three-piece ensemble as an “orchestra.”) And on the flip side: Does a typical audience member really notice the difference?

One thing is sure: The amount Broadway/San Diego is charging for “Wizard of Oz” tickets is comparable to that for the full-orchestra “West Side Story” — with a top price (including fees) of about $120.